Draw a neat and labelled diagram showing the reproduction in amoeba. Answer the following questions :
(a) Is reproduction in amoeba of the sexual or asexual kind ?
(b) Name the specific kind of reproduction which occurs in amoeba.
(c) How many offsprings are produced from one division?
(d) What kind of cell division occurs during the reproduction in amoeba?
(e) Give one more example of an organism which reproduces by the same mode of reproduction as that of amoeba.
Labelled diagram showing the reproduction in amoeba is shown below:
(a) Reproduction in amoeba is asexual.
(b) Amoeba reproduces by binary fission.
(c) Two offsprings are produced from one division.
(d) During the reproduction in amoeba, the type of cell division that occurs is mitosis.
(e) E. coli also reproduces by binary fission.
Reproduction in Animals – Interactive Study Guide
Reproduction ensures the continuation of species. Animals reproduce sexually (fusion of gametes) or asexually (single parent, no gametes). This chapter also covers embryo development and cloning.
Sexual vs Asexual Reproduction
| Feature | Sexual | Asexual |
|---|---|---|
| Parents | Two (male + female) | One |
| Gametes | Required (sperm + egg) | Not required |
| Offspring | Genetically different (variation) | Genetically identical (clones) |
| Examples | Humans, frogs, birds | Amoeba, Hydra, yeast |
Fertilisation Types
Inside female body. Fewer eggs, better protection. Examples: humans, birds, dogs.
Outside body (in water). Many eggs, lower survival. Examples: frogs, fish, starfish.
Development Sequence
Zygote (1 cell) divides → Embryo (ball of cells, implants in uterus) → Foetus (recognisable body parts) → Birth (~9 months in humans)
Nutrition via placenta through umbilical cord.
Asexual Reproduction Types
- Budding: Bud grows from parent → detaches (Hydra, yeast)
- Binary fission: Parent splits into 2 equal parts (Amoeba, bacteria)
- Fragmentation: Body breaks into fragments, each grows (Planaria, starfish)
Cloning: Dolly the Sheep
First cloned mammal (1996). Ian Wilmut, Roslin Institute, Scotland. Nucleus from donor cell → enucleated egg → embryo → surrogate mother → Dolly (genetic copy of donor).
Self-Test Questions
- What is the difference between internal and external fertilisation?
- Differentiate between viviparous and oviparous animals with examples.
- Describe binary fission in Amoeba.
- What is IVF? Why is it called "test-tube baby"?
- How was Dolly the sheep cloned?